The present invention relates generally to microfilm equipment and in particular to a peripheral indexing machine that is adapted to be utilized in combination with a microfilmer or a microfilm reader to automatically generate an index for a roll of microfilm.
When recording documents on microfilm, it is conventional to have each page of the document(s) rcorded on a separate frame of film. Hence, each each frame of the microfilm corresponds to a single page from the document(s). Typically, the microfilming apparatus places a dark spot, called a marker or "blip", on each frame of the film as the documents are being filmed. The markers are provided for later use by a microfilm reader having "scanning" or "searching" capabilities to count the frames on the reel and automatically advance the film through the reader to the desired document. For an explanation of a sensing circuit for a microfilm reader of this type, see U.S. Pat. No. 4,219,737, issued Aug. 26, 1980, entitled Self Regulating Detection Circuit, assigned to the assignee of the present invention.
The sophistication of the marking system provided by a microfilmer machine varies with the particular machine utilized. Presently, most machines simply place a single marker on each frame of the reel. Some machines, however, provide the additional capability of placing markers above, as well as below, the image on the film. Such a capability can be utilized to identify particular documents as well as specific pages of a document. More particularly, if a document is comprised of 50 pages, for example, an upper marker would be placed on each page of the document and a lower marker would be placed only on the first page of the document. When this is done for all of the documents on a roll of microfilm, it will be appreciated that the upper markers will serve as document indicators and the lower markers will serve as page indicators. Thus, a search request of 10/18 would produce the eighteenth page of the tenth document on the reel. Still other microfilmers have the capability of placing markers of varying lengths on the film to provide further degrees of specificity, such as "page", "chapter" and "book" designations.
However, despite the increasing sophistication of document identification for searching and scanning by microfilm readers, when a reel of microfilm is initially recorded, the index for the reel is still generated manually. In other words, while the documents are being microfilmed, an individual typically records by hand the name of each document and the "address" or location of the document on the reel. Since a typical reel of microfilm may have several thousand frames, it can readily be appreciated that this can be an extremely tedious and time consuming task. Moreover, if a mistake is made in generating the index, it can later lead to the retrieval of improper documents.
It is therefore the primary purpose of the present invention to provide a microfilm indexing machine that automatically generates an index for a reel of microfilm either while the documents are initially being recorded or from an existing roll of microfilm. When utilized in combination with a marker or "blip" generating microfilmer, the present invention permits the operator to enter via a keyboard up to twenty alpha-numeric characters to identify a particular document. Then entry is printed on a paper tape and can optionally be recorded on a magnetic tape and/or a "floppy" disc. The microfilm indexing machine of the present invention then automatically prints adjacent the identification information appearing on the tape the address of the frame on the reel of film where the document will appear. Generally speaking, this is accomplished by counting the markers being created by the microfilmer as the pages of the documents are being filmed. The count is incremented for each frame regardless of whether a document identification entry is made or not. Thus, as will subsequently be described in greater detail, each time an entry is made, the proper address or "blip" retrieval number will automatically be reproduced adjacent the entry on the paper tape. In this manner, an operator can readily compile a complete page locating index for the contents of any given reel of microfilm. In addition, as will readily be appreciated by those skilled in the art, the paper tape may at anytime during the microfilming operation be cut and then microfilmed to provide partial indexing points within the reel. When this is done with a microfilm machine having a multiple blip capability, these partial index points can be "flagged" with upper track blips, for example, so that the indexes can be easily accessed later by an appropriately equipped microfilm reader. Furthermore, upon completion of the reel, the entire page locating index can be microfilmed and spliced to the start of the reel for easy reference.
The present indexing machine is also adaptable for use with a microfilm reader for generating an index for an existing roll of microfilm. In particular, the indexing machine can be "tapped" into the "blip" counting apparatus of the microfilm reader to monitor the frames on the roll. The operator can thus advance the film, stop it where desired, and enter appropriate identifying information on the paper tape. The indexing machine will then automatically print the address location of the frame on the paper tape.
Finally, it will be noted that the present invention may in some cases be utilized to generate indexes for microfilm having no marker identification. Specifically, certain microfilm readers, such as the aforementioned device disclosed in U.S. Pat. No. 4,219,737, issued Aug. 26, 1980, assigned to the assignee of the present invention, have the capability of adjusting their optical sensors which are normally used to read the "blips" on the microfilm, so that the sensors sense entire pages instead of blips. The present indexing machine can then utilize this image sensing information in the same manner as the blip information described previously to automatically count the frame on the roll of microfilm.
Additional objects and advantages of the present invention will become apparent from a reading of the detailed description of the preferred embodiment which makes reference to the following set of drawings in which :